Laser level units are well known in the construction and home improvement industries, and are used for producing a level plane of light to be used as a reference line for various applications. For example, the level line can be used when installing a drop ceiling, in carpentry for leveling cabinets or shelving, and when electrical conduit and junction boxes are being installed. The addition of a laser plumb line to the laser level line is also known. Uses of such a combination of the level and plumb lines, which create a cross-line, include aligning tiles on both floors and walls and creating cutouts for doors and windows during construction. The laser assemblies that create such level and plumb lines are normally mounted upon a mounting structure that includes a pendulum so that the level and plumb positions are automatically arrived at when the pendulum reaches equilibrium.